The research described in this proposal seeks to increase our knowledge concerning the fever response in animals other than humans; specifically relating to (1) the generality of the fever response in reptiles, (2) if there is a dose-response relationship between the level of bacteria infection in a reptile and the magnitude and duration of the fever response, (3) the relationship of the acute phase response to the increase in body temperature (which typically defines a fever), and (4) the occurrence of the fever response in a species of mammal (the California ground squirrel, Spermophilus beecheyi) living in its natural environment. Fever responses have been demonstrated in 7 lizards species, 3 snakes species, and 2 turtles species. However, a number of other species of reptiles have not exhibited a fever response upon injection with putative pyrogenic agents. We plan to test more species of reptiles to better define the parameters under which a fever will be demonstrated. A second set of experiments will explore possible dose-response relationships regarding the magnitude and duration of the fever response. Experiments reported in the literature have generally used a single dose of either live or dead bacteria in an attempt to demonstrate a fever response. We believe that more information can be obtained if more detailed studies use a wide range of bacteria dosages. A third set of experiments will better define the relationship between the level of bacteria infection, the presence or absence of the fever response as defined by a significant increase in body temperature, and certain aspects of the acute phase response. Specifically we will look at the aspects of the acute phase response that involve decreases in serum iron and zinc levels and increases in circulating white blood cell counts. A fourth set of experiments will study the response of a free-living mammal to bacteria infection. The physiological response of an animal maintained under laboratory conditions is not always the same as under natural conditions. Therefore, data gathered on the fever response in the natural environment is important for a better understanding of the fever phenomenon. Students will be involved in all aspects of this research project including data design, collection, and analysis, utilization of various pieces of scientific equipment, writing of scientific papers, and presentation of results at scientific meetings.